1. Field of the Invention
The present invention relates to an apparatus for and a method of effecting a load test on an apparatus such as a power supply apparatus or a power amplifier for supplying electric power to a load.
2. Description of the Related Art
When a load test is effected on an apparatus such as a power supply apparatus or a power amplifier for supplying electric power to a load, a load test is executed in such a manner that an apparatus to be tested is connected to a load apparatus as a substitute for an actual load.
In the above-mentioned load test, resistors and semiconductors have been used as a load apparatus so far.
Since, however, resistors and semiconductor consume all of electric power and convert it to produce heat, the above-mentioned related-art load test entails the following shortcomings (a) and (b).
(a): Since all of electric power supplied from a tested apparatus to a load apparatus is consumed by the load apparatus, not only electric power consumed by the tested apparatus itself but also electric power supplied from the tested apparatus to the load apparatus should be supplied to the tested apparatus by a suitable means such as a commercially-available power supply. For this reason, electric charges increase unavoidably so that the load test becomes expensive.
(b): In order to prevent temperature from rising within facilities due to heat produced from the load apparatus, a load test should be performed within the facilities of wide space or the load test should be performed while air-conditioning facilities or cooling apparatus are being operated. Moreover, in order to prevent the load apparatus from being damaged due to heat produced by the load apparatus itself, the load apparatus should be made large in size (surface area of the load apparatus should be widened in order to efficiently diverge heat). As a consequence, from these standpoints, the tested apparatus and the test method become expensive and preparations for the load test become cumbersome.
The above-mentioned shortcomings become remarkable particularly when the tested apparatus is an apparatus which outputs a large output current or particularly when a load test may be executed for a long period of time so as to examine aging changes of the tested apparatus.
In view of the aforesaid aspect, it is an object of the present invention to provide a regenerative load apparatus and a load test method in which the shortcomings encountered in the related art when a load test is effected on an apparatus such as a power supply apparatus or a power amplifier for supplying electric power to a load can be removed.
It is another object of the present invention to provide a regenerative load apparatus and a load test method in which a test cost required when a load test is effected on an apparatus for supplying electric power to a load can be decreased considerably.
According to an aspect of the present invention, there is provided a load apparatus for testing an apparatus, which supplies electric power to a load, as a tested apparatus. This regenerative load apparatus is comprised of a first load for transmitting supplied electric power from an output side at a current conversion ratio approximately inverse relative to that of the tested apparatus, a second load for consuming supplied electric power and a power supply for supplying electric power to the tested apparatus as is approximately equal to electric power consumed by the second load, wherein electric power is diverged and supplied to the first and second loads from the tested apparatus and the electric power transmitted from the first load is supplied to the tested apparatus in addition to the electric power from the power supply. Specifically, electric power is regenerated from the first load to the tested apparatus.
According to this regenerative load apparatus, since the output current of the tested apparatus becomes considerably larger than an input current to the second load, electric power supplied from the tested apparatus to the regenerative load apparatus can become considerably larger than the electric power consumed by the second load. Therefore, most of the electric power supplied from the tested apparatus to the regenerative load apparatus except the electric power consumed by the second load can be regenerated from the first load to the tested apparatus.
Then, since the power supply apparatus supplies the electric power approximately equal to the electric power consumed by the second load to the tested apparatus, the electric power supplied from the power supply to the tested apparatus becomes considerably smaller than the electric power supplied from the tested apparatus to the regenerative load apparatus. Specifically, the electric power supplied from the power supply to the tested apparatus becomes considerably smaller than electric power supplied from a suitable means such as a commercially-available power supply when a load test is executed by a load apparatus using a resistor or a semiconductor.
As described above, since the electric power supplied from the power supply to the tested apparatus can be decreased considerably, the aforementioned shortcoming (a) encountered in the related art can be eliminated.
Further, since only part of the electric power supplied from the tested apparatus to the regenerative load apparatus is consumed by the regenerative load apparatus, the regenerative load apparatus produces heat which is less intensive than that of the related-art load apparatus due to consumption of electric power. Thus, the aforementioned shortcoming (b) encountered in the related art also can be removed.
According to another aspect of the present invention, there is provided a load apparatus for testing an apparatus, which supplies electric power to a load, as a tested apparatus. This regenerative load apparatus is comprised of a first load for transmitting supplied electric power from an output side and whose current conversion ratio can be varied, a second load for consuming supplied electric power, a power supply for supplying electric power to said tested apparatus and whose output voltage can be varied and a control means for controlling the current conversion ratio of the first load and the output voltage of the power supply in unison with each other, wherein electric power is diverged and supplied to the first and second loads from the tested apparatus and the electric power transmitted from the first load is supplied to the tested apparatus in addition to the electric power from the power supply.
According to this regenerative load apparatus, as described above, since the electric power supplied from the power supply to the tested apparatus can be decreased considerably, the aforementioned shortcoming (a) encountered in the related art can be eliminated.
Further, since only part of the electric power supplied from the tested apparatus to the regenerative load apparatus is consumed by the regenerative load apparatus, the regenerative load apparatus produces heat which is less intensive than that of the related-art load apparatus due to consumption of electric power. Thus, the aforementioned shortcoming (b) encountered in the related art also can be eliminated.
Furthermore, according to this regenerative load apparatus, since the output current of the tested apparatus can be increased up to a desired target value by controlling the current conversion ratio of the first load and the output voltage of the power supply in unison with each other, a load test can be effected on a variety of tested apparatus.
According to still another aspect of the present invention, there is provided a load apparatus for testing an apparatus, which supplies electric power to a load, as a tested apparatus. This regenerative load apparatus is comprised of a first load for transmitting supplied electric power from an output side, a second load for consuming supplied electric power and whose equivalent resistance value can be varied, a power supply for supplying electric power to the tested apparatus and a control means for controlling the equivalent resistance value of the second load, wherein electric power is diverged and supplied to the first and second loads from the tested apparatus and the electric power transmitted from the first load is supplied to the tested apparatus in addition to the electric power from the power supply.
According to this regenerative load apparatus, as described above, since the electric power supplied from the power supply to the tested apparatus can be decreased considerably, the aforementioned shortcoming (a) encountered in the related art can be overcome.
Further, since only part of the electric power supplied from the tested apparatus to the regenerative load apparatus is consumed by the regenerative load apparatus, the regenerative load apparatus produces heat which is less intensive than that of the related-art load apparatus due to consumption of electric power. Thus, the aforementioned shortcoming (b) encountered in the related art also can be overcome.
Furthermore, according to this regenerative load apparatus, since the output current of the tested apparatus can be increased to a desired target value by controlling the equivalent resistance value of the second load, a load test can be effected on a variety of tested apparatus.
In the above-mentioned regenerative load apparatus according to the present invention, the first load is a switching power supply.
Further, in the above-mentioned regenerative load apparatus according to the present invention, the first load is a power amplifier.
According to a further aspect of the present invention, there is provided a method of effecting a load test on a tested apparatus which is an apparatus for supplying electric power to a load. This load test method is comprised of the steps of diverging and supplying electric power to a first load, which transmits supplied electric power from an output side, and a second load, which consumes supplied electric power, from the tested apparatus, supplying the electric power transmitted from said first load to the tested apparatus in addition to electric power from a power supply and controlling a current conversion ratio of the first load and an output voltage of the power supply in unison with each other.
According to this load test method of the present invention, as described above, since the electric power supplied from the power supply to the tested apparatus can be decreased considerably, the aforementioned shortcoming (a) encountered in the related art can be overcome.
Further, since only part of the electric power supplied from the tested apparatus to the regenerative load apparatus is consumed by the regenerative load apparatus, the regenerative load apparatus produces heat which is less intensive than heat of the related-art load apparatus due to consumption of electric power. Thus, the aforementioned shortcoming (b) encountered in the related art also can be overcome.
Furthermore, according to this load tested apparatus, since the output current of the tested apparatus can be increased up to a desired target value by controlling the current conversion ratio of the first load and the output voltage of the power supply in unison with each other, a load test can be effected on a variety of tested apparatus.
According to yet a further aspect of the present invention, there is provided a method of effecting a load test on a tested apparatus which is an apparatus for supplying electric power to a load. This load test method is comprised of the steps of
diverging and supplying electric power to a first load, which transmits supplied electric power from an output side, and a second load, which consumes supplied electric power, from the tested apparatus, supplying the electric power transmitted from the first load to the tested apparatus in addition to electric power from a power supply and controlling an equivalent resistance value of the second load.
According to this load test method, as described above, since the electric power supplied from the power supply to the tested apparatus can be decreased considerably, the aforementioned shortcoming (a) encountered in the related art can be overcome.
Further, since only part of the electric power supplied from the tested apparatus to the regenerative load apparatus is consumed by the regenerative load apparatus, the regenerative load apparatus produces heat which is less intensive than that of the related-art load apparatus due to consumption of electric power. Thus, the aforementioned shortcoming (b) encountered in the related art also can be overcome.
Furthermore, according to this load tested apparatus, since the output current of the tested apparatus can be increased to a desired target value by controlling the equivalent resistance value of the second load, a load test can be effected on a variety of tested apparatus.
In the above-mentioned load tested apparatus according to the present invention, the first load is a switching power supply.
Further, in the above-mentioned load tested apparatus according to the present invention, the first load is a power amplifier.